Hence the two lines, 4# and 15#. The purpose was to provide a sampling. Any additional lines you'd suggest would be good try.

If lighter lines do not get the loop, then is that because of some reason other than strength?

If you can do it, how about something in the 20# range or higher? It seems from these discussions that many salt anglers use tippets in those strengths.

I don't use the loop knot for lighter lines because I'm using smaller flies at that point (trout, panfish, etc.) and I prefer something that cinches right up to the hook eye for those. I prefer not to use loops with smaller flies because sometimes the loop is almost as big as the fly, and I believe that can make the presentation a bit unnatural. So to answer your question, it doesn't have anything to do with strength.

Geoff Wilson is probably the worlds best knot guy and I believe what he says. His fishing experience alone dwarf's most everyone I know. He says it is a 90% knot. I believe him and my results mirror its effectiveness. For trout flies most of the time you want a straight connection anyway, especially for dry flies. It is too easy to break 4 lb that an unscientific pull test using your hands means nothing.

One must also take into account that knots are not meant to be an all day affair. After each good fish you better retie and sharpen your hooks. It you do not you are only asking for trouble. Nowhere was this more apparent than earlier this season on the canal. Basser caught what was over a 40" fish. He eas using a slim beauty for his mono to braid connection on his spinning rig. The fish put up a good fight in the heavy canal current and was landed just fine. Next cast he hung up and the knot popped while he was barely applying pressure to try and free the hook. All knots loose effectiveness after being stretched by fish. You should have retied those knots,any number of them will fail after repeated strain.

Not to deviate too much, but I suspect (a theory) that comparative knot strength of various knots may be a function of the brand and type of line. I remember a Stren salesman that would demonstrate that 10# regular Stren was stronger than 12# Trilene XT. He used a shock test to demonstrate. Under a steady load the XT was much stronger. Could be that some lines test at near 100% with the non-slip loop and other brands don't. The knot strength of various knots may be a function of the line used to tie them.

Juro,
Terrific job! It is refreshing to get data, and your home tests are valid comparison data. The only suggestion I would offer for statistical significance would be to do each test a greater number of times.

Re usiing a needle for a nail knor or a uni-knot, a Geoff Wilson book illustrates that the unit-knot and nail knot are identical, tied by different methods. I proved this to myself by tying dozens of both with small diameter cord.

I wonder which change, the double overhand or the nail knot, conributed the most improvement?

I just did a two-trial test using 20 lb Trilene Big Game mono knotted to two 1/0 hooks hooked around two pen barrels and then pulled apart until something broke. First trial was an improved clinch knot (my usual knot) vs. a non-slip loop knot (the first I've tied in years, following the instructions from the first hit on Google: flyfishlouisania.com) The improved clinch knot failed at the knot. For the second trial, I used the existing non-slip loop knot and tied the broken end of the line back onto the second hook using a regular clinch knot because I didn't have enough tag end to do an improved clinch. This time the non-slip loop failed at the knot. Not exactly a controlled test with a sufficient number of trials, but I found the results interesting. More testing and results to follow.

Here's a little background info: For more than 30 years I have used the clinch knot or improved clinch knot to attach my line to the fly, swivel, hook or lure, with the only exception being that I would probably use a surgeon's loop to attach the line to a split-ring, punched metal lure or large-diameter hook (similar to a loop-to-loop connection: tie the loop, pass the loop through the split ring/eye, put the lure/hook back through the loop and seat the knot). I generally have good success with the improved clinch knot unless the line is old or abraded. I often use the same fly all day without retying. I usually use 20 lb fluoro in the salt and for carp, and I guarantee that I apply more than 8 lbs of pressure when necessary . In freshwater I do a lot of fishing with light tackle spinning gear and usually tie the line to a snap swivel (same connection as straight-eye hook) and regularly use the same swivel tied with the same improved clinch knot for multiple trips (3 or 4 or even more ), even with 6 lb test line. Without a doubt, regardless of equipment or type of knot used and excluding instances where the fish bites through the line or nicks/wraps the line on something, most of my line breakages occur while trying to land a fish by grabbing the line. I seldom have the line or knot fail in an open-water situation. Granted, when the line breaks it usually does occur at the knot unless the line was damaged ahead of the knot, but the clinch knot works just fine for me. I also use a blood knot for tippet/leader connections, which is basically two clinch knots against one-another, and those knots seldom fail. When I tie the clinch knot or blood knot, I wrap the tag end around the standing line, rather than twisting the loop to make the wraps. With a clinch knot I snug the knot carefully until it "rolls over" where the knot clinches the tag end (i.e., pull the standing line against the lure/fly until the knot starts to slip and then tightens down again, try it and you'll see what I mean). It's difficult to properly tighten the clinch knot when attaching heavy line to a small-diameter hook/swivel. You sometimes have to push the last wrap back over the line because it tries to go behind the hook eye, and you usually have to push the wraps down the standing line towards the eye as you tighten the knot. I don't worry about making the knot "roll over" with heavy line, especially when the hook or leader is likely to break before the tippet/hook connection.

FWIW, I have done some tests in the past with palomar knots and non-slip loop knots, and while I don't recall the specifics I do know that I decided that the clinch knot was much easier to tie and was just as good for my purposes.

Q

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The farther you can cast, the easier it is for a fish to take you into your backing. I seldom see my backing . . .

Great to hear you actually did some testing rather than relying on our own opinions. It is revealing isn't it?

Quote:

most of my line breakages occur while trying to land a fish by grabbing the line

That is exactly how my standard non-slip loops broke over the past weekend's field testing.

Also the fact that the regular clinch broke the non-slip knot could likely be a sign of how the knot degrades with stress, it never broke on the first thrashing fish but it did after several for me.

There is a mix of objective and subjective in your analysis but what I have found putting preferences aside is that the palomar or trilene does not break off when holding the line where other knots often do.

The IGFA considers the palomor to be the strongest knot. I am trying to find out how they arrived at that decision...

I've been trying to find a cheap/used tensile testing machine that we could do some serious trials on but no luck and the new rigs run a couple of grand. When people like Lefty say they have done this type of test I'm inclined to believe them, but it would be nice to see the results published.

If anyone knows of any sources on the web or in books, please shout. I'm talking about real stats - multiple trials - statistically significant sets of results etc.

To do this type of test justice would be a lot of effort but I think it would be very worthwhile. The absolute and relative performance of different knots on different brands of tippet, for different diameters would be extremely useful.

Maybe the manufacturers already do this?

Any engineering students (or better still teachers) out there with access to lab facilities? This would make a great college/high school applied physics project.

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When sight fishing, look over your shoulder from time to time, you never know who's behind you

Now double up the overhand with a 'weave', and instead of using a simple clinch use either a nail knot with the tag over the mainline (easy with a double end needle) or tie the uni-knot to tie my proposed "improved" non-slip.

Or as many do if you have confidence in the standard non-slip stick with that. My experience has been less than acceptable when compared to the palomar when it comes to strength and durability but clearly others have a different view. I'll be able to do some industry testing in August to see which knots are scientifically stronger FWIW.

Millions still use the clinch and swear by it although it's clearly a weaker knot.

I'll still only use a loop in a small percentage of situations. When it comes to striper fishing, bonefishing, or other venues I can (and have) stood side by side with friends who are using a loop and I've caught as many or more fish with a fixed palomar knot and never feel it's the knot making a difference. Movement at the knot is just one tiny element of the angler's puzzle and I am not convinced it's all that critical with most flies that have active materials and designs.

Examples of flies where it might make a noticeable difference to fish are nylon braid body flies (which I never use due to stiffness), jiggy flies, hard poppers that ride stiff and those gummy sluggo imitations (I've never tried them so that's a guess).

Examples of flies where it probably makes very little are marabou, long materials, loop eye flies designed for fishing under current tension (e.g. turled), obviously tube flies, or essentially any fly that has a lot of resistance to push a lot of water due to the static tension that the bulk will create thus over-riding any freedom at the head.

Anyway I am very curious to see how our own knots fare in real testing machines.

Try tying the loop knot a slightly differant way. Instead of starting with a simple overhand knot, start with a figure eight knot. When bring back the tag end, follow the incoming path (same with the free end of the cinch) . I would be interested to hear what you get if you run a similar test series.